Restore foreign key.
Restore foreign key.


Former-commit-id: 9891e1754e55c92b5e9314c8496d62facbc27821
yingjunwu/peloton,jessesleeping/iso_peloton,apavlo/peloton,AngLi-Leon/peloton,haojin2/peloton,yingjunwu/peloton,wangziqi2016/peloton,vittvolt/15721-peloton,malin1993ml/peloton,ShuxinLin/peloton,apavlo/peloton,wangziqi2016/peloton,haojin2/peloton,apavlo/peloton,vittvolt/peloton,phisiart/peloton-p3,AngLi-Leon/peloton,yingjunwu/peloton,vittvolt/peloton,AngLi-Leon/peloton,jessesleeping/iso_peloton,cmu-db/peloton,AllisonWang/peloton,wangziqi2016/peloton,malin1993ml/peloton,cmu-db/peloton,cmu-db/peloton,prashasthip/peloton,malin1993ml/peloton,vittvolt/peloton,eric-haibin-lin/peloton-1,ShuxinLin/peloton,eric-haibin-lin/peloton-1,cmu-db/peloton,AllisonWang/peloton,malin1993ml/peloton,PauloAmora/peloton,jessesleeping/iso_peloton,AllisonWang/peloton,malin1993ml/peloton,vittvolt/15721-peloton,wangziqi2016/peloton,PauloAmora/peloton,eric-haibin-lin/peloton-1,haojin2/peloton,jessesleeping/iso_peloton,AllisonWang/peloton,ShuxinLin/peloton,wangziqi2016/peloton,vittvolt/15721-peloton,jessesleeping/iso_peloton,eric-haibin-lin/peloton-1,yingjunwu/peloton,prashasthip/peloton,phisiart/peloton-p3,haojin2/peloton,yingjunwu/peloton,AngLi-Leon/peloton,jessesleeping/iso_peloton,prashasthip/peloton,phisiart/peloton-p3,haojin2/peloton,prashasthip/peloton,phisiart/peloton-p3,PauloAmora/peloton,AllisonWang/peloton,vittvolt/peloton,AngLi-Leon/peloton,vittvolt/15721-peloton,prashasthip/peloton,PauloAmora/peloton,seojungmin/peloton,prashasthip/peloton,apavlo/peloton,AngLi-Leon/peloton,seojungmin/peloton,seojungmin/peloton,malin1993ml/peloton,ShuxinLin/peloton,yingjunwu/peloton,phisiart/peloton-p3,cmu-db/peloton,PauloAmora/peloton,phisiart/peloton-p3,haojin2/peloton,apavlo/peloton,ShuxinLin/peloton,seojungmin/peloton,apavlo/peloton,wangziqi2016/peloton,vittvolt/peloton,vittvolt/peloton,ShuxinLin/peloton,PauloAmora/peloton,seojungmin/peloton,jessesleeping/iso_peloton,seojungmin/peloton,cmu-db/peloton,AllisonWang/peloton,vittvolt/15721-peloton,eric-haibin-lin/peloton-1,vittvolt/15721-peloton,eric-haibin-lin/peloton-1